The human body cools itself by air convection, evaporation of sweat, and sometimes direct conduction of heat. A costume tends to block air motion, so it stops air convection and reduces evaporation of sweat. I think 50% of bodily heat loss is via the head and neck, so these require special attention.
If your furry costume is skin tight, you will sweat until it is soggy. This is actually good because soggy fur conducts heat out to where the sogginess is evaporating - thus cooling you.
If your furry costume has some barrier (latex, glue, plastic, air, foam, etc) that blocks heat conduction and/or sweat, then you need alternate cooling.
1. Improve airflow - Hollow head/head with microfan
2. Use icepacks or alternate means of heat removal.
For Tabbe and Fatima, we used something called “Chili Necks” under our costumes. Used for outdoors and sports-types, it's kinda like little “ice blues” inside a cloth sleeve that velcroes around your neck. Put 'em in the freezer and they're good for two hours. This has the effect of your major arteries carrying coolness throughout your body. The one time we used them at Worldcon, I don't think we had them completely frozen, 'cause we had keep them just in ice we got from the hotel cube maker, but we did seem to feel more comfortable than we had when we wore the costumes at Archon.
On keeping cool in costume: See our previous comments on the Chili- neck. There's apparently a less bulky bandanalike thing that cools as well. Nora and a friend will be test driving them at CC. We'll report back.
From: Lex Nakashima
Subject: Staying Dry
One thing to try: Take your daily shower the day -before- you are to wear the suit. As cold a shower as you can manage. With luck, you'll “dry off” by morning (you absorb a lot of water through the skin when you shower, and will throw it right off again when in the costume!). I should be more specific: take the shower the -night- before, just before bedtime. Another thing to try: cotton sweat clothes or unitards (possibly even cotton thermal underwear). You want to both be able to absorbe the moisture and let it evaporate. Dressing in layers will aid this to some extent (and is the second best thing to a costume that really breathes well). If this is your own design, try to find areas to cheat: if the critter wears clothes, sew fur only into those areas that show (so the the bulk of the costume is nice, comfortable street clothes or whatever). Cold drinks (-water-) frequently taken also help a -lot-.
I've never been a fan of cool suits, especially after the Kevin Peter Hall incident (developed pneumonia + complications from HIV). The coldness around the lungs/chest area can cause water to condense in your lungs. Bad. I also tend to think that the theories about “air conditioning” are a waste of time (with the exception of fans and circulation). It takes a lot of energy to remove heat from things fast. Current technologies aren't capable of doing this in a wearable manner. And to even -think- of using liquid nitrogen or dry ice–I run screaming from the room. Both of these things are dangerous! Remember, one of the reasons the suit gets hot is the LACK OF AIR CIRCULATION! You will asphyxiate! YOU WILL BE AN EX-FURRY! Sheesh! Rule number four: if you wear a full costume, you will be hot and uncomfortable. Period.
From: Flinthoof Sharis, on staying dry and cool in costume;
What a burst in message traffic lately! It's a rare night that I go online to find less than 25 new Fursuit messages waiting!
Lessee…what do we have to contribute…
Cooling. NASCAR drives have had to fight the overheating problems associated with driving cars at 185 mph in 120F conditions with all the metal around them radiating heat, PLUS wearing the fire-retardant suit as well. Not exactly cool. They do use a 'cool-suit', that being a suit with many capillary tubes woven into the fabric and running water pumped through an ice chest in the car. Due to the high heat nearby, hypothermia is not a problem… but air flow is! All that air coming at you at 185+mph is HOT.
Perhaps the best way to minimize heat is to limit the area exposed as fur. Lex suggested it and I echo the idea of using street clothes with furry 'sleeves' between shirt and hand. Legs can be done the same way. You'll end up with a more slender and natural form that, well, is naturally form-fitting since it's you. :) Cooling with a good 5-12v electronics cooling fan will do wonders. Take a look at those nice CPU cooling fans coming out. Very quiet, good airflow, and low current draw. They could easily be put in the head in several locations with a belt pack for Ni-cads. Not too many either. They are very low current usage.
From: Teddy Ruxpin
Subject: Cooling, fur,…
From: David A. Holt (GCC/TEME)
How does one acheive proper cooling while in a furry costume in the bright sun (body and head)?
Simplest thing is cool your head (which is where your heat sensor is.) Put a fan in the top of the head to draw cool air through. Needs only a small battery to operate.
A cool suit designed to circulate cool water through plastic tubing around the wearer. These are used in professional racing
I tried making one of these. Problems:
1. Back-pressure from the small tubing means you need a good sized pump. I used a good windshield-washer pump. It needs quite a lot of power, so you need a good-sized battery for any prolonged use. Nascar suits used car 12V.
2. What to dump the heat into. Nascar uses a cooler full of ice in the passanger seat. Hardly practical for us. I tried one of those blue ice-pack things, wrapped in more tubes of water which it cools. Its bulky. Tended to slip out of the couls and the pack close to your skin tends to lead to local frost-bite.
3. It ends up weighing a lot. All that water in those pipes.
From: Silent Red
Subject: Re: Heat dissipation
These are just some thoughts on the subject right of the top of my head. This'll probally seem very obvious to some but maybe it'll help some others. (sorry if someone's already covered this - I'm backlogged with my email reading )
The best points to 'ventilate' are places where your blood vessels are close to your skin, Namely your head, wrists and hands, ankles and feet. To a lesser extent - underarms, inner elbows (where you get shots) and the back of the knees.
My gray kitty costume felt just slightly too warm when I didn't have my gloves on. When I put the gloves on I felt like I was going to melt into a puddle. Learn me to make cotton-palmed gloves! :> Also, taking the 'feet' off back in my room was always a pleasure - Whew! :>